Engraving method and pattern for increasing brilliance of flat cut gemstone

ABSTRACT

A method for creating an inexpensive diamond with good optical and light qualities. The method includes cutting the diamond with a girdle diameter and a plurality of pavilion main facets, and a total height that is about 25% to 40% of the girdle width, and forming a series of parallel lines into at least one of the pavilion main facets. The resulting gemstone has a plurality of pavilion main facets, the gemstone having a total height that is about 25% to 40% of the girdle diameter, and a polygon shape formed into at least some of the pavilion main facets or pavilion girdle facets. In another embodiment, a gemstone has a girdle having a width, a pavilion portion with a plurality of pavilion main facets and a plurality of girdle lower facets, and a polygon shape etched into at least some of the pavilion main facets and girdle lower facets.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent Application Ser. No. 62/276,428, filed Jan. 8, 2016, the disclosure of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

This invention relates to the field of gemstones and jewelry, and in particular to enhancing the optical and light qualities of a gemstone.

BACKGROUND

Probably without realizing it, most people assume that there is a perfect, or best, or ideal way to cut a diamond. Most of this thinking is probably based on studies conducted by Marcel Tolkowsky in the early twentieth century. Further details of his work, and various standards and nomenclature of diamonds and diamond-cutting are well laid out in U.S. Pat. No. 8,069,688, all of the disclosure of which is incorporated herein by reference.

Tolkowsky posited that there is a single, most favorable, way to cut a diamond, so as to maximize both the brilliance and the fire in a diamond. The specification Tolkowsky developed requires that the total depth of the diamond be 59.3% of the girdle diameter, and that the table diameter is 53% of the girdle diameter. The Tolkowsky specification further requires a 34.5 degree crown angle, and a 40.75 degree pavilion angle. This cut does result in a diamond with excellent brilliance and fire. A side view of such a diamond is shown in FIG. 1.

This invention relates to improvements to the gemstones described above and to solutions to some of the issues raised or not solved thereby.

SUMMARY OF THE INVENTION

The invention provides a method for creating an inexpensive diamond with good optical and light qualities. The method includes cutting the diamond with a girdle diameter and a plurality of pavilion main facets, and a total height that is about 25% to 40% of the girdle diameter, and forming a polygon shape into at least some of the pavilion main facets, or forming a series of substantially parallel lines into at least one of the pavilion main facets. The invention further provides a gemstone having a girdle of a predetermined diameter, a plurality of pavilion main facets, the gemstone having a total height that is about 25% to 40% of the girdle diameter, and a polygon shape formed into at least some of the pavilion main facets. Another aspect of the invention provides a gemstone having a girdle having a diameter, a plurality of pavilion main facets and a plurality of girdle lower facets, the gemstone having a total height that is about 25% to 40% of the girdle diameter, and a geometric pattern etched into at least some of the pavilion main facets and at least some of the girdle lower facets. Yet another aspect of the invention provides a gemstone having a girdle having a width, a pavilion portion with a plurality of pavilion main facets and a plurality of girdle lower facets, and a polygon shape etched into at least some of the pavilion main facets and girdle lower facets.

The invention further provides a cut diamond including a girdle portion having a girdle plane, the girdle portion having a substantially round shape. On one side of the girdle portion is a crown portion, the crown portion including a table facet having eight sides and thus an octagonal shape. Eight crown facets are arranged around the table facet and have three sides. Each of the eight crown facets has one side arranged adjacent to one of the eight sides of the table facet and arranged at an angle between 16-30 degrees with respect to the girdle plane. Eight upper girdle facets are arranged around the table facet and have three sides. Each of the upper girdle facets has one side arranged adjacent to the girdle, and the other two sides adjacent to adjacent crown facets. A pavilion portion is arranged on another side of the girdle portion diametrically opposite the crown portion. The pavilion portion tapers inward towards a culet at the bottom, as the pavilion portion extends away from the girdle plane. The pavilion portion includes sixteen girdle lower facets, each having a triangular shape with three sides and extending part way toward the culet, and each terminating in a point, short of the culet. One side of each of the sixteen girdle lower facets is arranged adjacent the girdle portion. The pavilion portion also includes eight pavilion main facets, each having four sides. Each one of the eight pavilion main facets is arranged between two pairs of the sixteen girdle lower facets, and each one of the eight pavilion main facets arranged at an angle between 28-30 degrees with respect to the girdle plane.

Other objects and advantages of the invention will become apparent hereainfter.

DESCRIPTION OF THE DRAWING

FIG. 1 is a side elevation view of a conventional round ideal cut diamond.

FIG. 2 is a side elevation view of a diamond that is cut according to one embodiment of the invention.

FIG. 3 is a top view of the diamond shown in FIG. 2.

FIG. 4 is a bottom view of the diamond shown in FIG. 2.

FIG. 5 is a side elevation view of a diamond cut according to the embodiment shown in FIGS. 2-4, and then further modified according to an aspect of the invention.

FIG. 6 is a side elevation view of the same gem as shown in FIG. 5, on an enlarged scale, showing a full strip of polygons formed in one facet, but only a portion of the gemstone.

FIG. 7 is a side elevation view of the same gem as shown in FIG. 6, on a further enlarged scale, still showing the full strip of polygons, but even a smaller portion of the gemstone.

FIG. 8 is a side elevation view mainly of one facet of the gemstone shown in FIG. 7, showing the strip of polygons according to the invention in even greater detail.

FIG. 9 is a side-by-side photograph of two gemstones of the same shallow depth, only the one on the right having had strips of polygons formed in some of the lower facets according to one embodiment the invention.

DETAILED DESCRIPTION

There are disadvantages to the ideal cut or the round brilliant cut for diamonds. Chief among those is that, although the table and girdle are well-perceived at any time, once the stone is set in a setting, the pavilion is generally not very visible, being covered by or receding into the setting. Accordingly, a buyer of a round brilliant cut gem is paying for relatively a lot of diamond weight that cannot be seen from the side. Generally this issue has not been perceived as major, as it was considered that the depth of pavilion was required, unavoidable in effect, in order to achieve enough brilliance to make the diamond look the way it is expected to look, sparkly, brilliant, fiery. Historically a diamond that did not have the necessary depth, in proportion to the diameter of the girdle, simply would not, it was believed, have that high level of light reflecting or refracting qualities returned to the observer, as later quantified and standardized by GemEx Systems, Inc., by means of its Light Performance® certification and nomenclature. So it was thought that the price simply had to be paid for the extra carat weight, so that the diamond looked as good as expected, once mounted.

As shown in FIG. 2, a gemstone 10 has a girdle portion 12 in a round or substantially round shape. A crown portion 14 extends from one side of the girdle portion 12, and a pavilion portion 16 extends from another side of the girdle portion. The crown portion 14 and pavilion portion 16 are on diametrically opposite sides of the girdle portion 12. The crown portion 14 and the pavilion portion 16 each have a plurality of facets. The girdle portion 12 can optionally be smooth or faceted. In these drawing figures, the girdle 12 is shown as smooth.

One aspect of the present invention provides a gemstone with much less height than a conventional brilliant cut gem, therefore having the advantage of being much less expensive, based on its lesser carat weight. As shown in FIG. 2, a gemstone 10 according to the present invention has a girdle portion 12 with a diameter d if the girdle is smooth. If the girdle portion is faceted, then the dimension d can be considered the girdle width, and is the distance between opposing facets. The gemstone 10 has a height h. According to the invention, the height h is no more than 40% of the girdle dimension d, and preferably about 35%. This compares to a conventional brilliant cut diamond wherein the ratio of height to girdle dimension is normally 60-65%.

As shown in FIGS. 2 and 3, the crown portion 14 includes a number of facets, namely, a table facet 18, and eight crown facets 20 generally triangular in shape, each contacting one side of the table facet with one side of the crown facet, and contacting the girdle 12 with a point. The crown portion 14 also includes eight upper girdle facets 22, also generally triangular in shape, alternating with the crown facets but inverted, contacting the table facet 18 with a point, and adjacent the girdle with a flat side. That is, each of the crown facets 20 is arranged between, and is adjacent, each adjacent pair of upper girdle facets 22.

As shown in FIGS. 2 and 4, the pavilion portion 16 also includes a number of facets. The pavilion portion 16 terminates in a culet 24 at the bottom of the gemstone 10. The culet 24 may simply be a point, or it may be a small facet called a culet facet, which is generally substantially parallel to the table facet 18, but facing opposite the table facet, and much smaller. That is, if the gemstone 10 is oriented such that the table facet 18 is substantially horizontal at the top of the gemstone, if the gemstone has a culet facet, the culet facet will be substantially horizontal at the bottom of the gemstone. Between the girdle 12 and the culet 24 there are two types of facets. There are sixteen girdle lower facets 26 (sometimes referred to as girdle half facets) which are substantially triangular, contacting the girdle 12 with a flat side, each extending part way toward the culet 24 and each terminating in a point, short of the culet. The pavilion portion 16 further includes eight pavilion main facets 28. Each pavilion main facet 28 is a quadrilateral, having one point contacting the girdle 12, having one point contacting the culet 24, and having the widest portion of each pavilion main facet positioned therebetween. Each girdle lower facet 26 has another girdle lower facet 26 on one side, and a pavilion main facet 28 on the other. That is, for the length of the girdle lower facets 26, each adjacent pair of pavilion main facets 28 has a pair of girdle lower facets 26 positioned therebetween. Beyond the point where the girdle lower facets 26 no longer extend, adjacent pavilion main facets 28 abut each other.

In describing proportions of gemstones, it is common to use the diameter of the girdle portion 12 as the basis for reference. As shown best in FIGS. 2 and 3, the gemstone 10 shown there has a girdle diameter of d. According to the invention, the overall height h of the gemstone is less than 40% of the girdle diameter d, more preferably in a range of 25-35%, and most preferably 34.8%. The table facet 18 has a width of size t, that is, the distance between opposing sides of the table, that is in a range of 79 to 88 percent of the girdle diameter d, and preferably 83.5% of the girdle diameter. The crown portion 14 has a height c that is in a range of about 3% to 7% of the girdle diameter d, and preferably about 5%. The pavilion portion 16 has a height p that is in a range of about 27-28% of the girdle diameter d, and preferably about 27.5%. According to the invention, the crown portion 14 makes an angle θ1 with the plane of the girdle 12 in the range of 16-30 degrees, and most preferably about 28 degrees. The pavilion main facets 28 form an angle θ2 with the plane of the girdle 12 in the range of 28-30 degrees, and most preferably about 29 degrees. A gemstone cut to these dimensions is most favorable for the application of the present invention. Such a gemstone will have a total of the crown angle and the pavilion angle of only about 44-60 degrees, and most preferably about 57 degrees, as opposed to the total of 75.25 degrees of the Tolkowsky specification. Such a gemstone will be most appropriate for this invention because it will be less expensive than a conventionally cut diamond, but will have nearly equal light performance.

The present invention provides a way to achieve a high measurement of light return on the Light Performance® scale, without requiring that the gem have the ideal proportions, in particular the conventional percentage of depth-to-diameter proportions. That way, a buyer can more affordably buy a diamond that has a larger overall diameter, that is, that looks face-up as big as a diamond of significantly greater carat weight. For example, a diamond of 0.2 carat manufactured with the method of the present invention will appear comparable to a 0.4 carat diamond. To use another example, a buyer could choose to buy a diamond manufactured using the present invention that is by its face-up diameter as big as a 2 carat diamond, though the carat weight would likely be closer to 1.25 carat weight. The commercial value of such diamonds is thus significantly increased when the present invention is applied.

According to the present invention, as shown best in FIGS. 4-8, some or all of the pavilion main facets 28, and possibly also at least some of the girdle lower facets 26, have a strip 30 or path formed in the surface of the facet, and extending a substantial portion of the length of the longer dimension of the facet, wherein a number of outer polygons 32 are physically formed, in a string adjacent to each other, into the surface of the facet. The outer polygons 32 may be formed by any suitable means, including but not limited to, etching, laser cutting, focused ion beam, and other means. The outer polygons 32 may have various numbers of sides, that is, six sides, or eight sides, or ten sides, or twelve sides, most preferably eight sides. Each of the outer polygons 32 thus formed is most preferably about 1700 microns between opposing sides. In the most preferred embodiment, eight outer polygons 32 are formed into the facet to form the path or strip 30, but other numbers of such polygons may be so formed. Within each such polygon are formed additional polygons of the same number of sides, progressively smaller, down to about double the width of the lines forming the polygons. In the preferred embodiment, each of the lines formed in the facet is about 1-2 microns wide, and spaced about 1-4 microns apart from adjacent lines. In the most preferred embodiments, each of the polygons is a regular polygon, that is, with all sides of equal length and with all angles equal. Also as can be seen best in FIGS. 7 and 8, from the line of connection 34 between each adjacent pair of outer polygons 32 is formed a series of angled lines 36, progressively shorter, the further away from the polygons, so as to fill in the gaps between the adjacent outer polygons and form overall a generally smooth-sided path or strip 30. In an alternative embodiment, the strip 30 may be formed of a series of parallel lines, rather than polygons.

The present invention is a novel method of manufacturing a diamond in which the commercial value of the product of the invention is equal to, or competitive with, the commercial value of a traditionally cut jewelry grade diamond where no such close comparison of commercial value was ever possible before the present invention. The beneficial effect of this invention can be seen in FIG. 9, which is a side-by-side comparison of a gemstone before (on the left) and after (on the right) the invention described herein is applied. As can be seen there, there is substantially more brilliance and light reflectiveness in the gemstone to which the invention has been applied than the gemstone to which the invention has not been applied.

Although the invention has been herein described in what is perceived to be the most practical and preferred embodiments, it is to be understood that the invention is not intended to be limited to the specific embodiments set forth above. Rather, it is recognized that modifications may be made by one of skill in the art of the invention without departing from the spirit or intent of the invention and, therefore, the invention is to be taken as including all reasonable equivalents to the subject matter of the appended claims and the description of the invention herein. 

What is claimed is:
 1. A method for creating an inexpensive diamond with good optical and light qualities, the method comprising: cutting the diamond with a girdle diameter and a plurality of pavilion main facets, and a total height that is about 25% to 40% of the girdle diameter; and forming a polygon shape into at least some of the pavilion main facets.
 2. A method as recited in claim 1 further comprising forming the polygon shape by use of a chemical etching process.
 3. A method as recited in claim 1 wherein at least some of the polygon shapes formed in the pavilion main facets are formed in a shape that has opposing sides.
 4. A method as recited in claim 1 wherein the cut diamond is formed with a total height that is about 35% of the girdle diameter.
 5. A method for creating an inexpensive diamond with good optical and light qualities, the method comprising: cutting the diamond with a girdle diameter and a plurality of pavilion main facets, and a total height that is about 25% to 40% of the girdle diameter; and forming a series of substantially parallel lines into at least one of the pavilion main facets.
 6. A method as recited in claim 5 wherein the parallel lines are used to form polygons.
 7. A method as recited in claim 5 wherein the cut diamond is formed with a total height that is about 35% of the girdle diameter.
 8. A gemstone having: a girdle of a predetermined diameter; a plurality of pavilion main facets; the gemstone having a total height that is about 25% to 40% of the girdle diameter; and a polygon shape formed into at least some of the pavilion main facets or pavilion girdle facets.
 9. A gemstone as recited in claim 8 wherein the polygon shape is formed as a result of a chemical etching process.
 10. A gemstone as recited in claim 8 wherein at least some of the polygon shapes in the pavilion main facets are of a shape that has opposing sides, and are of a size such that the distance between opposing sides is about 1700 microns.
 11. A gemstone as recited in claim 8 wherein the gemstone has a total height that is about 35% of the girdle diameter.
 12. A gemstone as recited in claim 8 further comprising a crown portion with a height that is about 5% of the girdle diameter.
 13. A gemstone as recited in claim 12 further comprising a table facet having has a width that is about 83.5% of the girdle diameter.
 14. A gemstone having: a girdle having a diameter; a plurality of pavilion main facets and a plurality of girdle lower facets; the gemstone having a total height that is about 25% to 40% of the girdle diameter; and a geometric pattern etched into at least some of the pavilion main facets and at least some of the girdle lower facets.
 15. A gemstone as recited in claim 14 wherein the total height of the gemstone is about 35% of the girdle diameter.
 16. A gemstone as recited in claim 14 wherein eight polygons are formed in a strip on at least one of the pavilion main facets.
 17. A gemstone as recited in claim 14 wherein the geometric pattern includes a series of substantially parallel lines, each about 1-2 microns wide, and spaced about 1-4 microns apart from adjacent lines.
 18. A gemstone as recited in claim 14 wherein the pavilion main facets are part of a pavilion portion, and wherein the girdle exists in a plane, and wherein the pavilion main facets form an angle with the plane of the girdle that is about 28-30 degrees.
 19. A gemstone as recited in claim 18 further comprising a crown portion having crown facets, and wherein the crown facets form an angle with the plane of the girdle that is about 28 degrees.
 20. A gemstone having: a girdle having a width; a pavilion portion with a plurality of pavilion main facets and a plurality of girdle lower facets; and a polygon shape etched into at least some of the pavilion main facets and girdle lower facets.
 21. A gemstone as recited in claim 20 having a height that is no more than 40% of the girdle width.
 22. A gemstone as recited in claim 21 having a crown portion that has a height that is within a range of 3% to 7% of the girdle width.
 23. A gemstone as recited in claim 22 wherein the pavilion portion has a height that is within a range of 27% to 28% of the girdle width.
 24. A gemstone as recited in claim 23 having a table facet that has a width that is within a range of 79% to 88% of the girdle width.
 25. A cut diamond comprising: a girdle portion having a girdle plane, the girdle portion having a substantially round shape; a crown portion on one side of the girdle portion, the crown portion including: a table facet having eight sides, the table facet having an octagonal shape, eight crown facets arranged around the table facet and having three sides, each one of the eight crown facets having one side arranged adjacent to one of the eight sides of the table facet and arranged at an angle between 16-30 degrees with respect to the girdle plane, eight upper girdle facets arranged around the table facet and having three sides, each one of the upper girdle facets having one side arranged adjacent to the girdle, and having the other two sides adjacent to adjacent crown facets; and a pavilion portion arranged on another side of the girdle portion diametrically opposite the crown portion and having a culet, the pavilion portion tapering inward towards the culet as the pavilion portion extends away from the girdle plane, the pavilion portion including: sixteen girdle lower facets, each having a triangular shape with three sides and extending part way toward the culet and each terminating in a point, short of the culet, one side of each of the sixteen girdle lower facets arranged adjacent the girdle portion; and eight pavilion main facets, each having four sides, and each one of the eight pavilion main facets arranged between two pairs of the sixteen girdle lower facets, each one of the eight pavilion main facets arranged at an angle between 28-30 degrees with respect to the girdle plane.
 26. A cut diamond as recited in claim 25 wherein the girdle portion has a width, and the cut diamond has a height that is no more than 40% of the girdle width.
 27. A cut diamond as recited in claim 26 further comprising a culet facet formed at the culet.
 28. A cut diamond as recited in claim 27 wherein the crown portion has a height that is within a range of 3% to 7% of the girdle width.
 29. A cut diamond as recited in claim 28 wherein the pavilion portion has a height that is within a range of 27% to 28% of the girdle width.
 30. A cut diamond as recited in claim 29 wherein the table facet has a width that is within a range of 79% to 88% of the girdle width. 